Abstract
Microsatellite instability is a widely known and sought after tumor marker. Among other things, its prevalence and role in the development of gastric adenocarcinoma are being studied. However, the profile of microsatellite instability during precancerous changes in the gastric mucosa (atrophy, intestinal metaplasia, epithelial dysplasia) remains insufficiently studied. The purpose of this literature review is to assess the possibility of using microsatellite instability status as a diagnostic and predictive marker of precancerous changes and lesions of the gastric mucosa. A systematic review of publications in the PubMed database was conducted using a search query based on the combination of the terms “microsatellite instability” (“MSI”), “stomach/gastric cancer/adenocarcinoma”, “stomach/gastric dysplasia/intraepithelial neoplasia”, “stomach/gastric precancerous lesions” for the period from 1997 to 2023. Review articles were excluded from the search results. The systematic review included 11 relevant publications. Despite the lack of a uniform methodology and diversity in the study groups, all publications demonstrated an increase in the level of microsatellite instability in the range from normal (unchanged) gastric mucosa and/or its precancerous changes to gastric cancer: among precancerous changes in the gastric mucosa, the most common subject of study was intestinal metaplasia, where levels of microsatellite instability ranged from 0 to 53.3%, while its levels in gastric cancer ranged from 32.6 to 76.7%. The results of the studies included in the review may indicate a possible predictive role of microsatellite instability in precancerous changes in the gastric mucosa in relation to the risk of developing cancer.